System for transmitting and reproducing pictures



May 10 1927. l 1,627,701

M, c. HALL.

SYSTEM FOR TRANSMITTING AND REPRODUCING PICTURES Filed'nec. 2Q, 192s 2 sham-shewv 1 41) 12] If/J' ,5. 10) [14 1E) v l/l/I/l '/lll, j

INVENTOR By /KL El@ ATTORNEY ',6Z7,70l May 10, 1927. M. C. HALL n SYSTEM FOR TRANSMITTNG AND REPROIUC'LNG PICTURES Filedec.` 20, 1923 2 Sheets-Sheet 2 ATTORNEY Patented May 10, 1927.

UNITED STATES PATENT oFF1cE.

MERTON C. HALL, OF NEW YORK, N. Y.,`ASSIGNOR T AMERICAN TELEPHONE'AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

SYSTEM FOR TRANSMITTING AND REPRODUCING PICTURES.

Application led December 20, 1923. Serial No. 681,850.

The principal object of my invention is to provide a new and improved method and suitable apparatus for transmitting pictures to a distance and reproducing them at the receiving point. Another object of myl invention is to provide for reproducing a trans mitted-picture byV means ot an air brush di rected to successive elements of a picture receiving surface. Another object' is to transmit code combinations corresponding to the ldegree of light or shade of the successive picture elements and to operate an air brush 'at thereceiving end governed in accordance l with these coden combinations. These and l5 various other objects of my invention will become apparent on consideration of a' disclosure of one way in whichmy invention may be practiced. It will be understood that ,the following specification relates to this particular embodiment of the invention and that the invention is defined in the appended claims.

Referring to the drawings, Figure 1 is a .diagram of apparatus at the transmitting end; Fig. 2 is a side elevation of the picture recording apparatus at the receiving end; Fig. 3 is a corresponding end elevation; Fig. 4 is a corresponding top plan view;

, andFig. 5 is a diagram of the. receiving 39 apparatus.

At thetransmitting end the picture in the form of a semi-transparent film 12 is wrapped on the glass drum 13 which is rotated step by step, and traversed relative ly slowly in the direction'of its axis hy the y engagement of the screw threads y14 with the i rack '15. Light from the source 10 is reflected hy the mirror 11 Within the drum 13 through the film 12 a'nd the hole 17 in the screen 16 and is focused by the'lens 18 on the photoelectric cell v19.

The quantity of light falling on the photoelectric cell 19 governs the currentl in circuit therewith and therefore determines the voltage on the grid of the three-electrode vacuum tube amplifier 20. Thus it will. be seen that the output current of'I the amplifier 2O will vary in accordance with the degree of shade inthe film 12 at the with the hole 17.1

The output current from the amplifier 2O passes through three marginal relays in series, 21` 22 and 23. The adjustments are made so that for white in the picture none of these relays picks up; forlight grey 21 only part thereof in registry picks up; for dark grey 21 and 22, but not 23. pick up; and 'for black all three of them pick up.

. It will readily he seen in "Fig. 1 that the circuits are so arranged that the magnets 24 and 25 are energized accordingr to the following table :v magnet 24 or 25, when energized, determines that a hole shall he punched in the corresponding position on a tape 30, which is advanced step by step to correspond with the stepped rotation of the drum 13. @ne manner oi controlling the tape punching and -feeding operations is disclosed in the cepending application, Serial No. 681,853, iiied ADecember 20, 1923. Said application aiso discloses means for automatically punching the carriage .return and line 'feed codes in adclition to the codes representing the picture s a es.

Marginal Relays relays.

24 and 25. Code' Dark grey 21 22 25 Both.

vThe shades referred to in the first column punch out a similar tape. The received tape 3l in Fig. 2 determines the operation of an air brush. which will next he described, as shown in Figs. 2` 3 and 4. The air brush indicated generally' by the numeral. 32 receives compressed air through the conduit L and ink lfrom the well O, and thequantity of inl; delivered is determined by the extent to which the valve lever C is depressed. Thev air brush 32 is supported by the standard A on the base B which alsov carries Ithe supports J for the two magnets I and I. When energized, these magnets cause their respective armatures K and K to press down on the respective ends of the floating lever D which rests across the valve lever C. By means of the armature back stops M and M land the stops N and N in the guides H and H', the range of travel of the ends of they lever D is determined. As shown in Figs. 3 and 4, a certain displacement of `the arma- I line.

ture of magnet I will depress the valve lever C only about half as muchas the corresponding displacement of the armature of magnet I. Accordingly when neither I nor I is energized, the valve is closed; when I alone is energized, the valve is opened to a degree that wemay call .one unit; when I is energized, the air brush valve isopencd two units; and when both I and I arevciiergized, the air brush valve is opened three vstep by step before the air brush 32, and at each stepit receives ink from the air brush 32 so that if the airbrush valve is closed, the impressed shade is white; if open one unit, the impressed shade'is light grey; if open two units, dark grey; and if open three units, black.

Between the picture receiving surface 33 and the nozzle of the air brush 32 is a screen 41 with a hole defining an element of the picture. The screen stops the sprayed ink except at the holel and limits and defines the element of the surface 33 to which the ink is applied. i

Fig. 5 shows circuit arrangements suitable for controlling-the various functions of the receivingr device. The tape at the transmitting end as prepared in the manner hereinbefore described is employed to send code impulses over the line and by means of well known apparatus,`a similar tape is rodiiced at the receiving end. This tape 31 is passed through the tape transmitter 50 to control a page printer with which is associated the distributor 39. vThe brushes of distributor 39 make one revolution for each code coinbination in the tape 31. Just after the magnets I and I have been operated, brush 41 engages segment S, and operates ma net 35 which causes the paper 33 to be a vanced across its length one step. At the saine time, brush 43 engages segment T and o crates the tape feed magnet 34, advancing t e tape to the next position.` When a carriage return combination occurs in the tape, relay 45 is operated andfin turn operates the carriage return magnet 46 to restore the paper 33.*to its initial position at the beginning of the lVhen the carriage 'starts to return,

t-lie contacts 47 are mechanically closed,

causing relay 48 tooperate. The o eration of relay 48 at. ,this time prevents t e letter spacing, operation during the return of the paper carriage. When the carriage is completely returned, contacts 47 open to release relay 48 and to condition magnet 35 for subsequent operation. The occurrence of aline feed signal combination in tape 31 operates magnet 49 to advance the paper one step in thc direction of its length. This process is repeated' until each linear element of the picture 'l2 is tested and reproduced on the page printer.

I claim:

l. The method et transmitting a picture which consists in making a record in code l'orm corresponding to the characteristicsof the picture-elements, transmitting current impulses to reproduce said record, applying coloring material to a surface at the receiving end, and electrically governing said application by the reproduced record.

2. The method ot' transinittin a picture which consists in making a mec anical record corresponding to the characteristics of successive-picture elements, transmitting curi ent impulses under control of said record .to reproduce said record at the receiving end,

applying coloring material to a surface at the receiving end, and electrically governin said application by the reproduced recor 3. In combination, an air brush, a valve controlling its operation, and two ma ets connected to'operate said valve additively, the effect of one magnet alone being doub e that of the other 4ma et alone.

4. Picture transmitting and reproducing means comprising means to punch a tape in accordance with L,the de ee of light and shade ofthe successive e ements of the pic-A ture to be transmitted, means to send current impulses to reproduce a similar tapent the receiving end, a picture receivin ,surface, an air brush, means to move sai surface relatively to said air brush, and means to control the airbrush by the tape produced at the receiving end.V

5. The method of transmitting a picture which consists in making a record incode.

form corresponding` to the characteristics of the picture elements, transmitting current impulses to reproduce said record, spraying eolorin material on a `surface at the receiving en and governing said spraying by the reproduced record.

6. In combination, an air brush, a picture receiving surface before it, a screen with a` hole between them defining a picture element, means tostep the receiving surface along to present successive elements beforethe hole. and means to adjust the air brush to put the proper shades on the respective elements.

7 In combination, an air brush, a picture receiving surface before it, a screen with a.

hole between them defining a picture element, means to step the receiving surface along to present successive elements before izo noemer the hole, and means to adjust'the air brush to put the proper shades on the respective elements in accordance with received code currents transmitting a picture.

8. Picture transmitting and reproducing mechanism comprising means for making a,

perforated record in accordance with the characteristics of successive elements of the plcture tofbe transmitted, means under control of the perforated l'ecord for sending current impulses to reproduce a similar record, a receiving surface, a device for properforated record in accordancewith the characteristic shades of successive elements of the lcture to be transmitted, means under 'contro of the perforated record for sending current impulses to reproduce a similar record, a receiving surface, a device for projecting ink upon said surface, meansfor 25 ,moving said surface relatlvel to said device, and means to control said device and the movement of said surface by the repro'- duced record.

10. Picture transmitting and reproducing :zo

mechanism comprising means for makin a record in code combinations correspondlng to the chalacteristics-of successive elements of the picturel to be transmitted, means under` control of the record for sending current`35 impulses to reproduce a similar record, a receiving surface, an air brush for projecting coloring material upon said surface, means for moving said surface relatively to said air brush, and means tol control said airA brush and the movement of said surface by the reproduced record. v

In testimony whereof, I have signed my name to this specification this 19th day of December, 1923.

BIERTON C. HALL. 

